1. Field of the Invention
The present invention relates, in general, to creating realistic skin for robots or for use with robotics or other applications in which skin or similar coverings are applied (e.g., robotics used to simulate movement of a human's or a character's face, hands, or the like), and, more particularly, to methods of designing and fabricating skin assemblies such as skin for applying over robotics where such methods are more efficient and repeatable (e.g., are not as reliant upon artist or craftsman time and talents).
2. Relevant Background
Durable materials that are often also flexible and elastic such as plastics and rubbers are used in many applications to create coverings or skins that are applied over an internal physical support structure or skeleton. For example, skins or skin systems are used to create realistic models of humans, animals, and characters, and when combined with robotics, such models may accurately simulate live beings.
Robotics involves the design and use of robots such as to provide programmable actuators or drivers to perform tasks without human intervention, and there have been significant demands for robotic devices (or robots as these terms may be used interchangeably) that simulate humans, animals, and other living beings or characters. These robotic characters are relied upon heavily in the entertainment industry such as to provide special effects for movies and television and to provide robots for use in shows and displays in amusement or theme parks. For example, robotics may be used to provide a character in a theme park ride or show that repeats a particular set of movements or actions (e.g., programmed tasks) based on the presence of guests or a ride vehicle or another triggering event.
It is likely that the interest in robotics will continue to expand in the coming years, and a growing area of interest is how to provide robots that appear more realistic. Many robotics companies have focused on creating robots with software, processing hardware, and mechanical actuators or drivers that allow the robots to behave more like the natural creature that is being simulated. Much work has been done to create robots that can move and even behave similar to humans such as by manipulating objects with mechanical assemblies that behave like hands configured to be human-like. Significant effort has also been directed to providing robots with realistic facial animation such as having a robot open and close its mouth to provide lip synchronization with output audio (e.g., with speech) and by providing particular facial movements including eye movement such as frowning, smiling, and the like. While many advances have been made in realistically simulating the physical movement and facial movement of a character, problems with maintaining a realistic or desired movement or facial animation still occur when the robotics (e.g., internal components of a robot including mechanical/structural portions as well as software, hardware, power systems, and the like) are covered with a skin or skin system. For example, a robot used to simulate a particular creature would be covered with skin or a covering assembly to imitate the natural or desired covering for the creature such as skin and fur/hair for many creatures, clothes for some creatures such as humans or characters (e.g., characters from animated films or television or puppets), or more fanciful covering system such as a metallic suit or any other desired covering.
In simulating humans or human-like characters, the robotics are typically covered in a skin that is fabricated of flexible material to move naturally with the underlying robotics. The skin may be formed of a rubber material or a silicone that is attached or anchored to the mechanical actuators or drivers of the robotic system, and the skin is configured to have an outward appearance similar to the character or creature being simulated by the robot. For example, the facial skins can be formed so as to have an uncanny resemblance to the character (or person) they are imitating, but often this resemblance ends when the attached robotics begin animating the face. The connection or anchoring points become apparent as the skin is pulled or pushed from behind. Additionally, the movement may be undesirably localized with movement only at the appoint of attachment, whereas a human face generally stretches and contracts more as a unit (or the movement is more widespread across the face), e.g., a human's skin around their nose and eyes may move when skin around the mouth moves while a typical robotic skin may only move near the connection point with the manipulating robotics. Efforts have been made to try to create a material for use as the skin for robotics, and especially for a facial skin for human-like robots, but most of these materials still only provide a layer of skin that has a tendency to move at the point of attachment.
Currently, a skin system for a robot is made using a manual process relying on skill and experience of the craftsperson creating the skin and requiring many man-hours to prototype and later fabricate based on the prototype. In the existing process, a sculpture is created, such as from clay or other moldable/shapeable materials, to represent the exterior skin shape (e.g., a person's face, a character from a movie, and so on). The sculpture is then molded, and sheet wax or a layer of clay is laid by hand into this exterior mold to define a desired thickness for the exterior skin layer. An interior core is then fabricated by hand such as by using fiberglass and resin, and this core may be configured to include skin attachment points to allow robotics to later be attached or anchored to the skin. A fiberglass or similar material is used to form a mold from this core, and hard shells, e.g., fiberglass shells to support the skin when the robot is later assembled, are then created from this core mold. An exterior skin can finally be formed by pouring a rubber or other flexible material into the gap between the exterior mold (with the sheet wax removed) and the core mold. After it is set, the skin is removed from the molds and placed on the supporting or hard shell(s) and attached to portions of the robotics.
Skin fabrication has been a cumbersome process and animation (or transfer of mechanical forces applied by the robotics) has often not met the needs of the robotics industry as the unitary skin reacts to the attached robotics in undesirable ways, which may include exposing the underlying robotics, moving only or mainly at the attachment point, and providing limited durability of skin at mounting or contact locations with the robotics. The skin typically is of a single material with one set of physical characteristics such as hardness, flexibility, and the like. Hence, there remains a need for improved methods for fabricating skin systems or assemblies for robotics and other applications that involve covering a support structure with a covering or skin. Preferably such fabrication methods would be less labor-intensive, would support use of multi-layers or components in the skin assembly, and would support design and prototype efforts such as more efficient alteration of component shapes, sizes, materials, and the like.